Abstract
This paper will provide an overview of the various processes for drying combustible powders with particular emphasis on spray, fluidized bed and ring dryers. FM Global, an industrial property insurance company, has seen numerous explosion and fire losses in these units that have caused extensive equipment damage with a serious impact on production and loss of sales. A number of large incidents have occurred in Europe and the UK.
The paper will review the loss history accumulated by FM Global over the last 25 years and point out overall causal factors as well as specific factors in the major processes. This also includes some information on incidents provided by a major manufacturer of process dryers.
There will be an overview of the processes with emphasis on operational parameters that can impact the hazard created by processing combustible dusts. While the systems can be quite different in size, function and operating conditions, a number of common hazards are present.
With the review of each major process type there will be a discussion of process hazards, key controls, alarms and interlocks and description of the protection and mitigation features that can be implemented to minimize the effects of fire and explosion events. This will emphasize FM Global loss prevention guidelines but will also indicate applicable NFPA and EU codes.
